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High Expansion Foams

Foam is a proportioned mixture of water and foam eoneentrate aspirated with air to eause expansion, e.g. from 6 to 10 times the volume (low expansion foam) up to >100 times (high expansion foam). It transports water to the surfaee of flammable liquids and enables it to float and extinguish the fire. An effeetive system depends upon ... [Pg.193]

High expansion foam systems-This is a concentration of air-filled bubbles resulting from the mechanical expansion of a foam solution to smother surface fires involving flammable liquids. [Pg.175]

Use of Highly Stabilized High-Expansion Foams in Fighting Forest Fires... [Pg.450]

High expansion foam, necessary for the coverage required in a woodland or grassland situation, usually loses its water content very rapidly (rate of water loss is called drainage). The remaining foam is then extremely dry and fragile, and susceptible to wind, water from other hoses, etc. (Table II). [Pg.451]

Typically, high expansion foams have characteristics similar to those in Table III. As expansion increases, drainage also increases. A foam with an expansion of 400 1 loses 33% of its water in the first 15 minutes after formation however, a foam with an expansion of 1000 1 loses 85% of its water in its initial fifteen minutes. [Pg.451]

Table III. Typical Parameters of High Expansion Foams... Table III. Typical Parameters of High Expansion Foams...
We have recently developed and obtained a patent for an ultra-stabilized high expansion foam (5 ) with expansion and drainage characteristics as shown in Table VI, using a polymeric additive for stabilization without harming expansion. [Pg.453]

Low expansion foams are typically applied to the surface of exposed flammable liquids, especially in outdoor areas. High expansion foams are commonly applied to large enclosed areas where high winds would not affect the foam usefulness and where interior locations are hard to reach. [Pg.214]

High expansion foam applied to special hazards such as warehouses or confined spaces. [Pg.214]

National Fire Protection Association (NFPA), NFPA 11 A. Medium and High Expansion Foam Systems. NFPA, Quincy, MA, 1990. [Pg.226]

High-expansion foam—expansion from 200 to 1,000 times foam to solution volume... [Pg.209]

Foam systems have more components requiring higher maintenance and have somewhat lower reliability than water-only systems. Low expansion foam systems do offer the advantage over high expansion foam of an effective "water only" discharge after the foam agent has been expended. "Water only" discharge can be detrimental in most situations that require foam application. Limitations on the use of foam include ... [Pg.209]

Some types of foam are not suitable for water miscible or polar solvent liquids. Special foams designed for fighting fires involving these materials are available. For more information on low-expansion foam systems refer to NFPA 11, Low-Expansion Foam Systems. For additional information on medium- and high-expansion foam systems, refer to NFPA 11 A, Medium- and High-Expan-sion Foam Systems. [Pg.210]

With the exception of high expansion foams, all other foams can be used in foam-water sprinkler system. However, AFFF is the most versatile agent because of its spreading capability and it can be applied through ordinary sprinkler heads. [Pg.219]

NFPA 11—Standard for Low-Fxpansion Foam NFPA 11A—Standard for Medium- and High-Expansion Foam Systems NFPA 12—Standard on Carbon Dioxide Extinguishing Systems NFPA 12A—Standard on Halon 1301 Eire Extinguishing Systems NFPA 13—Standard for the Installation of Sprinkler Systems NFPA 15—Standard for Water Spray fixed Systems for Fire Protection NFPA 25—Standard for the Inspection, Testingand Maintenance of Water-Based Fire Protection Systems... [Pg.351]

Respirable Dust—with the objective of providing improvements for protecting miners from exposure to respirable coal mine dust. Study areas have included (a) dust formation fb) dust control, and (c) dust measurement. Tests have included the infusion of water into coal beds for control of respirable dust the use of water-based, high-expansion foaming systems in conjunction with continuous mining machines, to reduce dust at the face the use of roam systems for dust suppression on conveyors and transfer points and the use of prototype dust meters. See also Pneumokonioses. [Pg.400]

Foams are categorized by their expansion ratio. Low-expansion foams have a ratio of 20 1 or less. The ratio of medium-expansion foam is 20 1 to 200 1 and for high-expansion foam it is 200 1 to 1000 1. AFFFs are typically low-expansion foams. [Pg.50]

High-expansion foam can be used as an effective vapor suppressant on LNG spills. It adds heat from the water in the foam to the vapors as they pass through the blanket. This procedure induces buoyancy which can reduce downwind concentrations at ground level. Expansion ratios of 750 1 to 1000 1 have been found to be particularly effective (NFPA 11 A, 1988). At the same time, a low-expansion foam in the 20 1 range would be effective for a hydrocarbon spill. As this shows, selection of the actual foam to be used must be based on the intended application and on the foam supplier s test data and recommendations. [Pg.51]

Fire extinguishing systems can include foam, carbon dioxide and dry chemical. Wetting agents and high expansion foam have been used in some plant protection systems. All fire e.xtinguishing systems should be evaluated for the potential health risks as well as overall effectiveness before incorporation into a plant. [Pg.158]


See other pages where High Expansion Foams is mentioned: [Pg.431]    [Pg.220]    [Pg.220]    [Pg.561]    [Pg.450]    [Pg.453]    [Pg.457]    [Pg.214]    [Pg.216]    [Pg.216]    [Pg.435]    [Pg.136]    [Pg.137]    [Pg.137]    [Pg.198]    [Pg.220]    [Pg.220]   
See also in sourсe #XX -- [ Pg.216 ]

See also in sourсe #XX -- [ Pg.337 ]




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